Purpose :
On the ocular surface, galectin-3, an endogenous carbohydrate-binding protein, colocalizes with membrane-associated mucins and contributes to the stabilization of the glycocalyx barrier. In this study, we investigated the response to nucleic acid stimulation in galectin-3 expression in immortalized corneal and conjunctival epithelium.

Methods :
Immortalized human corneal epithelial (HCLE) cells and human conjunctival epithelial (HCjE) cells were cultured on 12-mm Transwell filters (n=12) at a density of 4x105 cells/cm2. The cultured cells were then stimulated with 25µg/ml of polyinosinic-polycytidylic acid [Poly(I:C)], an analog of viral double-stranded RNA produced during viral replication. Transepithelial electrical resistance (TER) was then measured using EndOhm electrodes (World Precision Instruments). After 6-, 12-, and 24-hours exposure to Poly(I:C), the expressions of galectin-3 mRNA were analyzed by real-time polymerase chain reaction. The expressions of galectin-3 were analyzed by Western blotting. Immunoreactive bands were visualized by chemiluminescence, and densitometry analysis was then performed.

Conclusions :
The findings of this study show that Poly(I:C) challenge increases galectin-3 expression. We previously reported that Poly(I:C) challenge also increases the expression of membrane-associated mucins (ARVO 2016 & 2017). Our findings revealed that Poly(I:C) challenge, which mimics a viral infection, increases the barrier function of ocular-surface epithelia. Thus, we theorize that the increased barrier function must be a kind of host defense reaction to viral infection.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.